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bizhang_-obav/src/modules/local_position_estimator/BlockLocalPositionEstimator.cpp

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2015-10-24 10:57:46 -04:00
#include "BlockLocalPositionEstimator.hpp"
#include <mavlink/mavlink_log.h>
#include <fcntl.h>
#include <systemlib/err.h>
static const int MIN_FLOW_QUALITY = 100;
static const int REQ_INIT_COUNT = 100;
static const uint32_t VISION_POSITION_TIMEOUT = 500000;
static const uint32_t MOCAP_TIMEOUT = 200000;
static const uint32_t XY_SRC_TIMEOUT = 2000000;
using namespace std;
BlockLocalPositionEstimator::BlockLocalPositionEstimator() :
// this block has no parent, and has name LPE
SuperBlock(NULL, "LPE"),
// subscriptions, set rate, add to list
// TODO topic speed limiting?
_sub_status(ORB_ID(vehicle_status), 0, 0, &getSubscriptions()),
_sub_armed(ORB_ID(actuator_armed), 0, 0, &getSubscriptions()),
_sub_control_mode(ORB_ID(vehicle_control_mode),
0, 0, &getSubscriptions()),
_sub_att(ORB_ID(vehicle_attitude), 0, 0, &getSubscriptions()),
_sub_att_sp(ORB_ID(vehicle_attitude_setpoint),
0, 0, &getSubscriptions()),
_sub_flow(ORB_ID(optical_flow), 0, 0, &getSubscriptions()),
_sub_sensor(ORB_ID(sensor_combined), 0, 0, &getSubscriptions()),
_sub_distance(ORB_ID(distance_sensor),
0, 0, &getSubscriptions()),
_sub_param_update(ORB_ID(parameter_update), 0, 0, &getSubscriptions()),
_sub_manual(ORB_ID(manual_control_setpoint), 0, 0, &getSubscriptions()),
_sub_home(ORB_ID(home_position), 0, 0, &getSubscriptions()),
_sub_gps(ORB_ID(vehicle_gps_position), 0, 0, &getSubscriptions()),
_sub_vision_pos(ORB_ID(vision_position_estimate), 0, 0, &getSubscriptions()),
_sub_mocap(ORB_ID(att_pos_mocap), 0, 0, &getSubscriptions()),
// publications
_pub_lpos(ORB_ID(vehicle_local_position), -1, &getPublications()),
_pub_gpos(ORB_ID(vehicle_global_position), -1, &getPublications()),
_pub_filtered_flow(ORB_ID(filtered_bottom_flow), -1, &getPublications()),
_pub_est_status(ORB_ID(estimator_status), -1, &getPublications()),
// map projection
_map_ref(),
// block parameters
_integrate(this, "INTEGRATE"),
_flow_xy_stddev(this, "FLW_XY"),
_sonar_z_stddev(this, "SNR_Z"),
_lidar_z_stddev(this, "LDR_Z"),
_accel_xy_stddev(this, "ACC_XY"),
_accel_z_stddev(this, "ACC_Z"),
_baro_stddev(this, "BAR_Z"),
_gps_xy_stddev(this, "GPS_XY"),
_gps_z_stddev(this, "GPS_Z"),
_gps_vxy_stddev(this, "GPS_VXY"),
_gps_vz_stddev(this, "GPS_VZ"),
_gps_eph_max(this, "EPH_MAX"),
_vision_xy_stddev(this, "VIS_XY"),
_vision_z_stddev(this, "VIS_Z"),
_no_vision(this, "NO_VISION"),
_beta_max(this, "BETA_MAX"),
_mocap_p_stddev(this, "VIC_P"),
_pn_p_noise_power(this, "PN_P"),
_pn_v_noise_power(this, "PN_V"),
_pn_b_noise_power(this, "PN_B"),
// misc
_polls(),
_timeStamp(hrt_absolute_time()),
_time_last_xy(0),
_time_last_flow(0),
_time_last_baro(0),
_time_last_gps(0),
_time_last_lidar(0),
_time_last_sonar(0),
_time_last_vision_p(0),
_time_last_mocap(0),
// mavlink log
_mavlink_fd(open(MAVLINK_LOG_DEVICE, 0)),
// initialization flags
_baroInitialized(false),
_gpsInitialized(false),
_lidarInitialized(false),
_sonarInitialized(false),
_flowInitialized(false),
_visionInitialized(false),
_mocapInitialized(false),
// init counts
_baroInitCount(0),
_gpsInitCount(0),
_lidarInitCount(0),
_sonarInitCount(0),
_flowInitCount(0),
_visionInitCount(0),
_mocapInitCount(0),
// reference altitudes
_altHome(0),
_altHomeInitialized(false),
_baroAltHome(0),
_gpsAltHome(0),
_lidarAltHome(0),
_sonarAltHome(0),
_visionHome(),
_mocapHome(),
// flow integration
_flowX(0),
_flowY(0),
_flowMeanQual(0),
// reference lat/lon
_gpsLatHome(0),
_gpsLonHome(0),
// status
_canEstimateXY(false),
_canEstimateZ(false),
_xyTimeout(false),
// faults
_baroFault(FAULT_NONE),
_gpsFault(FAULT_NONE),
_lidarFault(FAULT_NONE),
_flowFault(FAULT_NONE),
_sonarFault(FAULT_NONE),
_visionFault(FAULT_NONE),
_mocapFault(FAULT_NONE),
//timeouts
_visionTimeout(true),
_mocapTimeout(true),
// loop performance
_loop_perf(),
_interval_perf(),
_err_perf(),
// kf matrices
_x(), _u(), _P()
{
// setup event triggering based on new flow messages to integrate
_polls[POLL_FLOW].fd = _sub_flow.getHandle();
_polls[POLL_FLOW].events = POLLIN;
_polls[POLL_PARAM].fd = _sub_param_update.getHandle();
_polls[POLL_PARAM].events = POLLIN;
_polls[POLL_SENSORS].fd = _sub_sensor.getHandle();
_polls[POLL_SENSORS].events = POLLIN;
// initialize P to identity*0.1
initP();
_x.setZero();
_u.setZero();
// perf counters
_loop_perf = perf_alloc(PC_ELAPSED,
"local_position_estimator_runtime");
//_interval_perf = perf_alloc(PC_INTERVAL,
//"local_position_estimator_interval");
_err_perf = perf_alloc(PC_COUNT, "local_position_estimator_err");
// map
_map_ref.init_done = false;
// intialize parameter dependent matrices
updateParams();
}
BlockLocalPositionEstimator::~BlockLocalPositionEstimator()
{
}
void BlockLocalPositionEstimator::update()
{
// wait for a sensor update, check for exit condition every 100 ms
int ret = poll(_polls, 3, 100);
if (ret < 0) {
/* poll error, count it in perf */
perf_count(_err_perf);
return;
}
uint64_t newTimeStamp = hrt_absolute_time();
float dt = (newTimeStamp - _timeStamp) / 1.0e6f;
_timeStamp = newTimeStamp;
//printf("dt: %0.5g\n", double(dt));
// set dt for all child blocks
setDt(dt);
// see which updates are available
bool flowUpdated = _sub_flow.updated();
bool paramsUpdated = _sub_param_update.updated();
bool baroUpdated = _sub_sensor.updated();
bool lidarUpdated = false;
bool sonarUpdated = false;
if (_sub_distance.updated()) {
if (_sub_distance.get().type == distance_sensor_s::MAV_DISTANCE_SENSOR_LASER) {
lidarUpdated = true;
}
if (_sub_distance.get().type == distance_sensor_s::MAV_DISTANCE_SENSOR_ULTRASOUND) {
sonarUpdated = true;
}
if (_sub_distance.get().type == distance_sensor_s::MAV_DISTANCE_SENSOR_INFRARED) {
mavlink_log_info(_mavlink_fd, "[lpe] no support to short-range infrared sensors ");
warnx("[lpe] short-range infrared detected. Ignored... ");
}
}
bool gpsUpdated = _sub_gps.updated();
bool homeUpdated = _sub_home.updated();
bool visionUpdated = _sub_vision_pos.updated();
bool mocapUpdated = _sub_mocap.updated();
// get new data
updateSubscriptions();
// update parameters
if (paramsUpdated) {
updateParams();
}
// update home position projection
if (homeUpdated) {
updateHome();
}
// check for timeouts on external sources
if ((hrt_absolute_time() - _time_last_vision_p > VISION_POSITION_TIMEOUT) && _visionInitialized) {
if (!_visionTimeout) {
_visionTimeout = true;
mavlink_log_info(_mavlink_fd, "[lpe] vision position timeout ");
warnx("[lpe] vision position timeout ");
}
} else {
_visionTimeout = false;
}
if ((hrt_absolute_time() - _time_last_mocap > MOCAP_TIMEOUT) && _mocapInitialized) {
if (!_mocapTimeout) {
_mocapTimeout = true;
mavlink_log_info(_mavlink_fd, "[lpe] mocap timeout ");
warnx("[lpe] mocap timeout ");
}
} else {
_mocapTimeout = false;
}
// determine if we should start estimating
_canEstimateZ = _baroInitialized && !_baroFault;
_canEstimateXY =
(_gpsInitialized && !_gpsFault) ||
(_flowInitialized && !_flowFault) ||
(_visionInitialized && !_visionTimeout && !_visionFault) ||
(_mocapInitialized && !_mocapTimeout && !_mocapFault);
if (_canEstimateXY) {
_time_last_xy = hrt_absolute_time();
}
// if we have no lat, lon initialized projection at 0,0
if (_canEstimateXY && !_map_ref.init_done) {
map_projection_init(&_map_ref, 0, 0);
}
// reinitialize x if necessary
bool reinit_x = false;
for (int i = 0; i < n_x; i++) {
// should we do a reinit
// of sensors here?
// don't want it to take too long
if (!isfinite(_x(i))) {
reinit_x = true;
break;
}
}
if (reinit_x) {
for (int i = 0; i < n_x; i++) {
_x(i) = 0;
}
mavlink_log_info(_mavlink_fd, "[lpe] reinit x");
warnx("[lpe] reinit x");
}
// reinitialize P if necessary
bool reinit_P = false;
for (int i = 0; i < n_x; i++) {
for (int j = 0; j < n_x; j++) {
if (!isfinite(_P(i, j))) {
reinit_P = true;
break;
}
}
if (reinit_P) { break; }
}
if (reinit_P) {
mavlink_log_info(_mavlink_fd, "[lpe] reinit P");
warnx("[lpe] reinit P");
initP();
}
// do prediction
predict();
// sensor corrections/ initializations
if (gpsUpdated) {
if (!_gpsInitialized) {
initGps();
} else {
correctGps();
}
}
if (baroUpdated) {
if (!_baroInitialized) {
initBaro();
} else {
correctBaro();
}
}
if (lidarUpdated) {
if (!_lidarInitialized) {
initLidar();
} else {
correctLidar();
}
}
if (sonarUpdated) {
if (!_sonarInitialized) {
initSonar();
} else {
correctSonar();
}
}
if (flowUpdated) {
if (!_flowInitialized) {
initFlow();
} else {
perf_begin(_loop_perf);// TODO
correctFlow();
//perf_count(_interval_perf);
perf_end(_loop_perf);
}
}
if (_no_vision.get() != CBRK_NO_VISION_KEY) { // check if no vision circuit breaker is set
if (visionUpdated) {
if (!_visionInitialized) {
initVision();
} else {
correctVision();
}
}
}
if (mocapUpdated) {
if (!_mocapInitialized) {
initmocap();
} else {
correctmocap();
}
}
_xyTimeout = (hrt_absolute_time() - _time_last_xy > XY_SRC_TIMEOUT);
if (!_xyTimeout && _altHomeInitialized) {
// update all publications if possible
publishLocalPos();
publishEstimatorStatus();
publishGlobalPos();
publishFilteredFlow();
} else if (_altHomeInitialized) {
// publish only Z estimate
publishLocalPos();
publishEstimatorStatus();
}
}
void BlockLocalPositionEstimator::updateHome()
{
double lat = _sub_home.get().lat;
double lon = _sub_home.get().lon;
float alt = _sub_home.get().alt;
mavlink_log_info(_mavlink_fd, "[lpe] home: lat %5.0f, lon %5.0f, alt %5.0f", lat, lon, double(alt));
warnx("[lpe] home: lat %5.0f, lon %5.0f, alt %5.0f", lat, lon, double(alt));
map_projection_init(&_map_ref, lat, lon);
float delta_alt = alt - _altHome;
_altHomeInitialized = true;
_altHome = alt;
_gpsAltHome += delta_alt;
_baroAltHome += delta_alt;
_lidarAltHome += delta_alt;
_sonarAltHome += delta_alt;
}
void BlockLocalPositionEstimator::initBaro()
{
// collect baro data
if (!_baroInitialized &&
(_sub_sensor.get().baro_timestamp[0] != _time_last_baro)) {
_time_last_baro = _sub_sensor.get().baro_timestamp[0];
_baroAltHome += _sub_sensor.get().baro_alt_meter[0];
if (_baroInitCount++ > REQ_INIT_COUNT) {
_baroAltHome /= _baroInitCount;
mavlink_log_info(_mavlink_fd,
"[lpe] baro offs: %d m", (int)_baroAltHome);
warnx("[lpe] baro offs: %d m", (int)_baroAltHome);
_baroInitialized = true;
if (!_altHomeInitialized) {
_altHomeInitialized = true;
_altHome = _baroAltHome;
}
}
}
}
void BlockLocalPositionEstimator::initGps()
{
// collect gps data
if (!_gpsInitialized && _sub_gps.get().fix_type > 2) {
double lat = _sub_gps.get().lat * 1e-7;
double lon = _sub_gps.get().lon * 1e-7;
float alt = _sub_gps.get().alt * 1e-3f;
// increament sums for mean
_gpsLatHome += lat;
_gpsLonHome += lon;
_gpsAltHome += alt;
_time_last_gps = _sub_gps.get().timestamp_position;
if (_gpsInitCount++ > REQ_INIT_COUNT) {
_gpsLatHome /= _gpsInitCount;
_gpsLonHome /= _gpsInitCount;
_gpsAltHome /= _gpsInitCount;
map_projection_init(&_map_ref, lat, lon);
mavlink_log_info(_mavlink_fd, "[lpe] gps init: "
"lat %d, lon %d, alt %d m",
int(_gpsLatHome), int(_gpsLonHome), int(_gpsAltHome));
warnx("[lpe] gps init: lat %d, lon %d, alt %d m",
int(_gpsLatHome), int(_gpsLonHome), int(_gpsAltHome));
_gpsInitialized = true;
if (!_altHomeInitialized) {
_altHomeInitialized = true;
_altHome = _gpsAltHome;
}
}
}
}
void BlockLocalPositionEstimator::initLidar()
{
if (_sub_distance.get().type != distance_sensor_s::MAV_DISTANCE_SENSOR_LASER) { return; }
// collect lidar data
bool valid = false;
float d = _sub_distance.get().current_distance;
if (d < _sub_distance.get().max_distance &&
d > _sub_distance.get().min_distance) {
valid = true;
}
if (!_lidarInitialized && valid) {
// increament sums for mean
_lidarAltHome += _sub_distance.get().current_distance;
if (_lidarInitCount++ > REQ_INIT_COUNT) {
_lidarAltHome /= _lidarInitCount;
mavlink_log_info(_mavlink_fd, "[lpe] lidar init: "
"alt %d cm",
int(100 * _lidarAltHome));
warnx("[lpe] lidar init: alt %d cm",
int(100 * _lidarAltHome));
_lidarInitialized = true;
}
}
}
void BlockLocalPositionEstimator::initSonar()
{
if (_sub_distance.get().type != distance_sensor_s::MAV_DISTANCE_SENSOR_ULTRASOUND) { return; }
// collect sonar data
bool valid = false;
float d = _sub_distance.get().current_distance;
if (d < _sub_distance.get().max_distance &&
d > _sub_distance.get().min_distance) {
valid = true;
}
if (!_sonarInitialized && valid) {
// increament sums for mean
_sonarAltHome += _sub_distance.get().current_distance;
if (_sonarInitCount++ > REQ_INIT_COUNT) {
_sonarAltHome /= _sonarInitCount;
mavlink_log_info(_mavlink_fd, "[lpe] sonar init: "
"alt %d cm",
int(100 * _sonarAltHome));
warnx("[lpe] sonar init: alt %d cm",
int(100 * _sonarAltHome));
_sonarInitialized = true;
}
}
}
void BlockLocalPositionEstimator::initFlow()
{
// collect pixel flow data
if (!_flowInitialized) {
// increament sums for mean
_flowMeanQual += _sub_flow.get().quality;
if (_flowInitCount++ > REQ_INIT_COUNT) {
_flowMeanQual /= _flowInitCount;
if (_flowMeanQual < MIN_FLOW_QUALITY) {
// retry initialisation till we have better flow data
warnx("[lpe] flow quality bad, retrying init : %d",
int(_flowMeanQual));
_flowMeanQual = 0;
_flowInitCount = 0;
return;
}
mavlink_log_info(_mavlink_fd, "[lpe] flow init: "
"quality %d",
int(_flowMeanQual));
warnx("[lpe] flow init: quality %d",
int(_flowMeanQual));
_flowInitialized = true;
}
}
}
void BlockLocalPositionEstimator::initVision()
{
// collect vision position data
if (!_visionInitialized) {
// increament sums for mean
Vector3f pos;
pos(0) = _sub_vision_pos.get().x;
pos(1) = _sub_vision_pos.get().y;
pos(2) = _sub_vision_pos.get().z;
_visionHome += pos;
if (_visionInitCount++ > REQ_INIT_COUNT) {
_visionHome /= _visionInitCount;
mavlink_log_info(_mavlink_fd, "[lpe] vision position init: "
"%f, %f, %f m", double(pos(0)), double(pos(1)), double(pos(2)));
warnx("[lpe] vision position init: "
"%f, %f, %f m", double(pos(0)), double(pos(1)), double(pos(2)));
_visionInitialized = true;
}
}
}
void BlockLocalPositionEstimator::initmocap()
{
// collect mocap data
if (!_mocapInitialized) {
// increament sums for mean
Vector3f pos;
pos(0) = _sub_mocap.get().x;
pos(1) = _sub_mocap.get().y;
pos(2) = _sub_mocap.get().z;
_mocapHome += pos;
if (_mocapInitCount++ > REQ_INIT_COUNT) {
_mocapHome /= _mocapInitCount;
mavlink_log_info(_mavlink_fd, "[lpe] mocap init: "
"%f, %f, %f m", double(pos(0)), double(pos(1)), double(pos(2)));
warnx("[lpe] mocap init: "
"%f, %f, %f m", double(pos(0)), double(pos(1)), double(pos(2)));
_mocapInitialized = true;
}
}
}
void BlockLocalPositionEstimator::publishLocalPos()
{
// publish local position
if (isfinite(_x(X_x)) && isfinite(_x(X_y)) && isfinite(_x(X_z)) &&
isfinite(_x(X_vx)) && isfinite(_x(X_vy))
&& isfinite(_x(X_vz))) {
_pub_lpos.get().timestamp = _timeStamp;
_pub_lpos.get().xy_valid = _canEstimateXY;
_pub_lpos.get().z_valid = _canEstimateZ;
_pub_lpos.get().v_xy_valid = _canEstimateXY;
_pub_lpos.get().v_z_valid = _canEstimateZ;
_pub_lpos.get().x = _x(X_x); // north
_pub_lpos.get().y = _x(X_y); // east
_pub_lpos.get().z = _x(X_z); // down
_pub_lpos.get().vx = _x(X_vx); // north
_pub_lpos.get().vy = _x(X_vy); // east
_pub_lpos.get().vz = _x(X_vz); // down
_pub_lpos.get().yaw = _sub_att.get().yaw;
_pub_lpos.get().xy_global = _sub_home.get().timestamp != 0; // need home for reference
_pub_lpos.get().z_global = _baroInitialized;
_pub_lpos.get().ref_timestamp = _sub_home.get().timestamp;
_pub_lpos.get().ref_lat = _map_ref.lat_rad * 180 / M_PI;
_pub_lpos.get().ref_lon = _map_ref.lon_rad * 180 / M_PI;
_pub_lpos.get().ref_alt = _sub_home.get().alt;
// TODO, terrain alt
_pub_lpos.get().dist_bottom = -_x(X_z);
_pub_lpos.get().dist_bottom_rate = -_x(X_vz);
_pub_lpos.get().surface_bottom_timestamp = 0;
_pub_lpos.get().dist_bottom_valid = true;
_pub_lpos.get().eph = sqrtf(_P(X_x, X_x) + _P(X_y, X_y));
_pub_lpos.get().epv = sqrtf(_P(X_z, X_z));
_pub_lpos.update();
}
}
void BlockLocalPositionEstimator::publishEstimatorStatus()
{
if (isfinite(_x(X_x)) && isfinite(_x(X_y)) && isfinite(_x(X_z)) &&
isfinite(_x(X_vx)) && isfinite(_x(X_vy))
&& isfinite(_x(X_vz))) {
_pub_est_status.get().timestamp = _timeStamp;
for (int i = 0; i < n_x; i++) {
_pub_est_status.get().states[i] = _x(i);
_pub_est_status.get().covariances[i] = _P(i, i);
}
_pub_est_status.get().n_states = n_x;
_pub_est_status.get().nan_flags = 0;
_pub_est_status.get().health_flags =
((_baroFault > 0) << SENSOR_BARO)
+ ((_gpsFault > 0) << SENSOR_GPS)
+ ((_lidarFault > 0) << SENSOR_LIDAR)
+ ((_flowFault > 0) << SENSOR_FLOW)
+ ((_sonarFault > 0) << SENSOR_SONAR)
+ ((_visionFault > 0) << SENSOR_VISION)
+ ((_mocapFault > 0) << SENSOR_MOCAP);
_pub_est_status.get().timeout_flags =
(_xyTimeout << 0)
+ (_visionTimeout << 1)
+ (_mocapTimeout << 2);
_pub_est_status.update();
}
}
void BlockLocalPositionEstimator::publishGlobalPos()
{
// publish global position
double lat = 0;
double lon = 0;
map_projection_reproject(&_map_ref, _x(X_x), _x(X_y), &lat, &lon);
float alt = -_x(X_z) + _altHome;
if (isfinite(lat) && isfinite(lon) && isfinite(alt) &&
isfinite(_x(X_vx)) && isfinite(_x(X_vy)) &&
isfinite(_x(X_vz))) {
_pub_gpos.get().timestamp = _timeStamp;
_pub_gpos.get().time_utc_usec = _sub_gps.get().time_utc_usec;
_pub_gpos.get().lat = lat;
_pub_gpos.get().lon = lon;
_pub_gpos.get().alt = alt;
_pub_gpos.get().vel_n = _x(X_vx);
_pub_gpos.get().vel_e = _x(X_vy);
_pub_gpos.get().vel_d = _x(X_vz);
_pub_gpos.get().yaw = _sub_att.get().yaw;
_pub_gpos.get().eph = sqrtf(_P(X_x, X_x) + _P(X_y, X_y));
_pub_gpos.get().epv = sqrtf(_P(X_z, X_z));
_pub_gpos.get().terrain_alt = 0;
_pub_gpos.get().terrain_alt_valid = false;
_pub_gpos.get().dead_reckoning = !_canEstimateXY && !_xyTimeout;
_pub_gpos.update();
}
}
void BlockLocalPositionEstimator::publishFilteredFlow()
{
// publish filtered flow
if (isfinite(_pub_filtered_flow.get().sumx) &&
isfinite(_pub_filtered_flow.get().sumy) &&
isfinite(_pub_filtered_flow.get().vx) &&
isfinite(_pub_filtered_flow.get().vy)) {
_pub_filtered_flow.update();
}
}
void BlockLocalPositionEstimator::initP()
{
_P.setZero();
_P(X_x, X_x) = 1;
_P(X_y, X_y) = 1;
_P(X_z, X_z) = 1;
_P(X_vx, X_vx) = 1;
_P(X_vy, X_vy) = 1;
_P(X_vz, X_vz) = 1;
_P(X_bx, X_bx) = 1e-6;
_P(X_by, X_by) = 1e-6;
_P(X_bz, X_bz) = 1e-6;
}
void BlockLocalPositionEstimator::predict()
{
// if can't update anything, don't propagate
// state or covariance
if (!_canEstimateXY && !_canEstimateZ) { return; }
if (_integrate.get() && _sub_att.get().R_valid) {
Matrix3f R_att(_sub_att.get().R);
Vector3f a(_sub_sensor.get().accelerometer_m_s2);
Vector3f b(_x(X_bx), _x(X_by), _x(X_bz));
_u = R_att * (a - b);
_u(U_az) += 9.81f; // add g
} else {
_u = Vector3f(0, 0, 0);
}
// dynamics matrix
Matrix<float, n_x, n_x> A; // state dynamics matrix
A.setZero();
// derivative of position is velocity
A(X_x, X_vx) = 1;
A(X_y, X_vy) = 1;
A(X_z, X_vz) = 1;
// derivative of velocity is accelerometer acceleration
// (in input matrix) - bias (in body frame)
Matrix3f R_att(_sub_att.get().R);
A(X_vx, X_bx) = -R_att(0, 0);
A(X_vx, X_by) = -R_att(0, 1);
A(X_vx, X_bz) = -R_att(0, 2);
A(X_vy, X_bx) = -R_att(1, 0);
A(X_vy, X_by) = -R_att(1, 1);
A(X_vy, X_bz) = -R_att(1, 2);
A(X_vz, X_bx) = -R_att(2, 0);
A(X_vz, X_by) = -R_att(2, 1);
A(X_vz, X_bz) = -R_att(2, 2);
// input matrix
Matrix<float, n_x, n_u> B; // input matrix
B.setZero();
B(X_vx, U_ax) = 1;
B(X_vy, U_ay) = 1;
B(X_vz, U_az) = 1;
// input noise covariance matrix
Matrix<float, n_u, n_u> R;
R.setZero();
R(U_ax, U_ax) = _accel_xy_stddev.get() * _accel_xy_stddev.get();
R(U_ay, U_ay) = _accel_xy_stddev.get() * _accel_xy_stddev.get();
R(U_az, U_az) = _accel_z_stddev.get() * _accel_z_stddev.get();
// process noise power matrix
Matrix<float, n_x, n_x> Q;
Q.setZero();
Q(X_x, X_x) = _pn_p_noise_power.get();
Q(X_y, X_y) = _pn_p_noise_power.get();
Q(X_z, X_z) = _pn_p_noise_power.get();
Q(X_vx, X_vx) = _pn_v_noise_power.get();
Q(X_vy, X_vy) = _pn_v_noise_power.get();
Q(X_vz, X_vz) = _pn_v_noise_power.get();
// technically, the noise is in the body frame,
// but the components are all the same, so
// ignoring for now
Q(X_bx, X_bx) = _pn_b_noise_power.get();
Q(X_by, X_by) = _pn_b_noise_power.get();
Q(X_bz, X_bz) = _pn_b_noise_power.get();
// continuous time kalman filter prediction
Matrix<float, n_x, 1> dx = (A * _x + B * _u) * getDt();
// only predict for components we have
// valid measurements for
if (!_canEstimateXY) {
dx(X_x) = 0;
dx(X_y) = 0;
dx(X_vx) = 0;
dx(X_vy) = 0;
}
if (!_canEstimateZ) {
dx(X_z) = 0;
dx(X_vz) = 0;
}
// propagate
_x += dx;
_P += (A * _P + _P * A.transpose() +
B * R * B.transpose() + Q) * getDt();
}
void BlockLocalPositionEstimator::correctFlow()
{
// flow measurement matrix and noise matrix
Matrix<float, n_y_flow, n_x> C;
C.setZero();
C(Y_flow_x, X_x) = 1;
C(Y_flow_y, X_y) = 1;
Matrix<float, n_y_flow, n_y_flow> R;
R.setZero();
R(Y_flow_x, Y_flow_x) =
_flow_xy_stddev.get() * _flow_xy_stddev.get();
R(Y_flow_y, Y_flow_y) =
_flow_xy_stddev.get() * _flow_xy_stddev.get();
float flow_speed[3] = {0.0f, 0.0f, 0.0f};
float global_speed[3] = {0.0f, 0.0f, 0.0f};
/* calc dt between flow timestamps */
/* ignore first flow msg */
if (_time_last_flow == 0) {
_time_last_flow = _sub_flow.get().timestamp;
return;
}
float dt = (_sub_flow.get().timestamp - _time_last_flow) * 1.0e-6f ;
_time_last_flow = _sub_flow.get().timestamp;
// calculate velocity over ground
if (_sub_flow.get().integration_timespan > 0) {
flow_speed[0] = (_sub_flow.get().pixel_flow_x_integral /
(_sub_flow.get().integration_timespan / 1e6f) -
_sub_att.get().pitchspeed) * // Body rotation correction TODO check this
_x(X_z);
flow_speed[1] = (_sub_flow.get().pixel_flow_y_integral /
(_sub_flow.get().integration_timespan / 1e6f) -
_sub_att.get().rollspeed) * // Body rotation correction
_x(X_z);
} else {
flow_speed[0] = 0;
flow_speed[1] = 0;
}
flow_speed[2] = 0.0f;
/* update filtered flow */
_pub_filtered_flow.get().sumx += flow_speed[0] * dt;
_pub_filtered_flow.get().sumy += flow_speed[1] * dt;
_pub_filtered_flow.get().vx = flow_speed[0];
_pub_filtered_flow.get().vy = flow_speed[1];
// TODO add yaw rotation correction (with distance to vehicle zero)
// convert to globalframe velocity
for (uint8_t i = 0; i < 3; i++) {
float sum = 0.0f;
for (uint8_t j = 0; j < 3; j++) {
sum += flow_speed[j] * PX4_R(_sub_att.get().R, i, j);
}
global_speed[i] = sum;
}
// flow integral
_flowX += global_speed[0] * dt;
_flowY += global_speed[1] * dt;
// measurement
Vector2f y;
y(0) = _flowX;
y(1) = _flowY;
// residual
Vector2f r = y - C * _x;
// residual covariance, (inverse)
Matrix<float, n_y_flow, n_y_flow> S_I =
(C * _P * C.transpose() + R).inverse();
// fault detection
float beta = sqrtf((r.transpose() * (S_I * r))(0, 0));
if (_sub_flow.get().quality < MIN_FLOW_QUALITY) {
if (!_flowFault) {
mavlink_log_info(_mavlink_fd, "[lpe] bad flow data ");
warnx("[lpe] bad flow data ");
_flowFault = FAULT_SEVERE;
}
} else if (beta > _beta_max.get()) {
if (!_flowFault) {
mavlink_log_info(_mavlink_fd, "[lpe] flow fault, beta %5.2f", double(beta));
warnx("[lpe] flow fault, beta %5.2f", double(beta));
_flowFault = FAULT_MINOR;
}
} else if (_flowFault) {
_flowFault = FAULT_NONE;
mavlink_log_info(_mavlink_fd, "[lpe] flow OK");
warnx("[lpe] flow OK");
}
// kalman filter correction if no fault
if (_flowFault == FAULT_NONE) {
Matrix<float, n_x, n_y_flow> K =
_P * C.transpose() * S_I;
_x += K * r;
_P -= K * C * _P;
// reset flow integral to current estimate of position
// if a fault occurred
} else {
_flowX = _x(X_x);
_flowY = _x(X_y);
}
}
void BlockLocalPositionEstimator::correctSonar()
{
if (_sub_distance.get().type != distance_sensor_s::MAV_DISTANCE_SENSOR_ULTRASOUND) {
return;
}
float d = _sub_distance.get().current_distance;
// sonar measurement matrix and noise matrix
Matrix<float, n_y_sonar, n_x> C;
C.setZero();
C(Y_sonar_z, X_z) = -1;
// use parameter covariance unless sensor provides reasonable value
Matrix<float, n_y_sonar, n_y_sonar> R;
R.setZero();
float cov = _sub_distance.get().covariance;
if (cov < 1.0e-3f) {
R(0, 0) = _sonar_z_stddev.get() * _sonar_z_stddev.get();
} else {
R(0, 0) = cov;
}
// measurement
Matrix<float, n_y_sonar, 1> y;
y(0) = (d - _sonarAltHome) *
cosf(_sub_att.get().roll) *
cosf(_sub_att.get().pitch);
// residual
Matrix<float, n_y_sonar, 1> r = y - C * _x;
// residual covariance, (inverse)
Matrix<float, n_y_sonar, n_y_sonar> S_I =
(C * _P * C.transpose() + R).inverse();
// fault detection
float beta = sqrtf((r.transpose() * (S_I * r))(0, 0));
if (d < _sub_distance.get().min_distance ||
d > _sub_distance.get().max_distance) {
if (!_sonarFault) {
mavlink_log_info(_mavlink_fd, "[lpe] sonar out of range");
warnx("[lpe] sonar out of range");
_sonarFault = FAULT_SEVERE;
}
} else if (beta > _beta_max.get()) {
if (!_sonarFault) {
mavlink_log_info(_mavlink_fd, "[lpe] sonar fault, beta %5.2f", double(beta));
warnx("[lpe] sonar fault, beta %5.2f", double(beta));
_sonarFault = FAULT_MINOR;
}
} else if (_sonarFault) {
_sonarFault = FAULT_NONE;
mavlink_log_info(_mavlink_fd, "[lpe] sonar OK");
warnx("[lpe] sonar OK");
}
// kalman filter correction if no fault
if (_sonarFault == FAULT_NONE) {
Matrix<float, n_x, n_y_sonar> K =
_P * C.transpose() * S_I;
_x += K * r;
_P -= K * C * _P;
}
_time_last_sonar = _sub_distance.get().timestamp;
}
void BlockLocalPositionEstimator::correctBaro()
{
Matrix<float, n_y_baro, 1> y;
y(0) = _sub_sensor.get().baro_alt_meter[0] - _baroAltHome;
// baro measurement matrix
Matrix<float, n_y_baro, n_x> C;
C.setZero();
C(Y_baro_z, X_z) = -1; // measured altitude, negative down dir.
Matrix<float, n_y_baro, n_y_baro> R;
R.setZero();
R(0, 0) = _baro_stddev.get() * _baro_stddev.get();
// residual
Matrix<float, n_y_baro, n_y_baro> S_I =
((C * _P * C.transpose()) + R).inverse();
Matrix<float, n_y_baro, 1> r = y - (C * _x);
// fault detection
float beta = sqrtf((r.transpose() * (S_I * r))(0, 0));
if (beta > _beta_max.get()) {
if (!_baroFault) {
mavlink_log_info(_mavlink_fd, "[lpe] baro fault, beta %5.2f", double(beta));
warnx("[lpe] baro fault, beta %5.2f", double(beta));
_baroFault = FAULT_MINOR;
}
// lower baro trust
S_I = ((C * _P * C.transpose()) + R * 10).inverse();
} else if (_baroFault) {
_baroFault = FAULT_NONE;
mavlink_log_info(_mavlink_fd, "[lpe] baro OK");
warnx("[lpe] baro OK");
}
// kalman filter correction if no fault
if (_baroFault == FAULT_NONE) {
Matrix<float, n_x, n_y_baro> K = _P * C.transpose() * S_I;
_x += K * r;
_P -= K * C * _P;
}
_time_last_baro = _sub_sensor.get().baro_timestamp[0];
}
void BlockLocalPositionEstimator::correctLidar()
{
if (_sub_distance.get().type != distance_sensor_s::MAV_DISTANCE_SENSOR_LASER) {
return;
}
float d = _sub_distance.get().current_distance;
Matrix<float, n_y_lidar, n_x> C;
C.setZero();
C(Y_lidar_z, X_z) = -1; // measured altitude,
// negative down dir.
// use parameter covariance unless sensor provides reasonable value
Matrix<float, n_y_lidar, n_y_lidar> R;
R.setZero();
float cov = _sub_distance.get().covariance;
if (cov < 1.0e-3f) {
R(0, 0) = _lidar_z_stddev.get() * _lidar_z_stddev.get();
} else {
R(0, 0) = cov;
}
Matrix<float, n_y_lidar, 1> y;
y.setZero();
y(0) = (d - _lidarAltHome) *
cosf(_sub_att.get().roll) *
cosf(_sub_att.get().pitch);
// residual
Matrix<float, n_y_lidar, n_y_lidar> S_I = ((C * _P * C.transpose()) + R).inverse();
Matrix<float, n_y_lidar, 1> r = y - C * _x;
// fault detection
float beta = sqrtf((r.transpose() * (S_I * r))(0, 0));
// zero is an error code for the lidar
if (d < _sub_distance.get().min_distance ||
d > _sub_distance.get().max_distance) {
if (!_lidarFault) {
mavlink_log_info(_mavlink_fd, "[lpe] lidar out of range");
warnx("[lpe] lidar out of range");
_lidarFault = FAULT_SEVERE;
}
} else if (beta > _beta_max.get()) {
if (!_lidarFault) {
mavlink_log_info(_mavlink_fd, "[lpe] lidar fault, beta %5.2f", double(beta));
warnx("[lpe] lidar fault, beta %5.2f", double(beta));
_lidarFault = FAULT_MINOR;
}
} else if (_lidarFault) { // disable fault if ok
_lidarFault = FAULT_NONE;
mavlink_log_info(_mavlink_fd, "[lpe] lidar OK");
warnx("[lpe] lidar OK");
}
// kalman filter correction if no fault
if (_lidarFault == FAULT_NONE) {
Matrix<float, n_x, n_y_lidar> K = _P * C.transpose() * S_I;
_x += K * r;
_P -= K * C * _P;
}
_time_last_lidar = _sub_distance.get().timestamp;
}
void BlockLocalPositionEstimator::correctGps() // TODO : use another other metric for glitch detection
{
// gps measurement in local frame
double lat = _sub_gps.get().lat * 1.0e-7;
double lon = _sub_gps.get().lon * 1.0e-7;
float alt = _sub_gps.get().alt * 1.0e-3f;
float px = 0;
float py = 0;
float pz = alt - _gpsAltHome;
map_projection_project(&_map_ref, lat, lon, &px, &py);
//printf("gps: lat %10g, lon, %10g alt %10g\n", lat, lon, double(alt));
//printf("home: lat %10g, lon, %10g alt %10g\n", _sub_home.lat, _sub_home.lon, double(_sub_home.alt));
//printf("local: x %10g y %10g z %10g\n", double(px), double(py), double(pz));
Matrix<float, 6, 1> y;
y.setZero();
y(0) = px;
y(1) = py;
y(2) = pz;
y(3) = _sub_gps.get().vel_n_m_s;
y(4) = _sub_gps.get().vel_e_m_s;
y(5) = _sub_gps.get().vel_d_m_s;
// gps measurement matrix, measures position and velocity
Matrix<float, n_y_gps, n_x> C;
C.setZero();
C(Y_gps_x, X_x) = 1;
C(Y_gps_y, X_y) = 1;
C(Y_gps_z, X_z) = 1;
C(Y_gps_vx, X_vx) = 1;
C(Y_gps_vy, X_vy) = 1;
C(Y_gps_vz, X_vz) = 1;
// gps covariance matrix
Matrix<float, n_y_gps, n_y_gps> R;
R.setZero();
// default to parameter, use gps cov if provided
float var_xy = _gps_xy_stddev.get() * _gps_xy_stddev.get();
float var_z = _gps_z_stddev.get() * _gps_z_stddev.get();
float var_vxy = _gps_vxy_stddev.get() * _gps_vxy_stddev.get();
float var_vz = _gps_vz_stddev.get() * _gps_vz_stddev.get();
// if field is not zero, set it to the value provided
if (_sub_gps.get().eph > 1e-3f) {
var_xy = _sub_gps.get().eph * _sub_gps.get().eph;
}
if (_sub_gps.get().epv > 1e-3f) {
var_z = _sub_gps.get().epv * _sub_gps.get().epv;
}
// TODO is velocity covariance provided from gps sub
R(0, 0) = var_xy;
R(1, 1) = var_xy;
R(2, 2) = var_z;
R(3, 3) = var_vxy;
R(4, 4) = var_vxy;
R(5, 5) = var_vz;
// residual
Matrix<float, 6, 1> r = y - C * _x;
Matrix<float, 6, 6> S_I = (C * _P * C.transpose() + R).inverse();
// fault detection
float beta = sqrtf((r.transpose() * (S_I * r))(0, 0));
uint8_t nSat = _sub_gps.get().satellites_used;
float eph = _sub_gps.get().eph;
if (nSat < 6 || eph > _gps_eph_max.get()) {
if (!_gpsFault) {
mavlink_log_info(_mavlink_fd, "[lpe] gps fault nSat: %d eph: %5.2f", nSat, double(eph));
warnx("[lpe] gps fault nSat: %d eph: %5.2f", nSat, double(eph));
_gpsFault = FAULT_SEVERE;
}
} else if (beta > _beta_max.get()) {
if (!_gpsFault) {
mavlink_log_info(_mavlink_fd, "[lpe] gps fault, beta: %5.2f", double(beta));
warnx("[lpe] gps fault, beta: %5.2f", double(beta));
mavlink_log_info(_mavlink_fd, "[lpe] r: %5.2f %5.2f %5.2f %5.2f %5.2f %5.2f",
double(r(0)), double(r(1)), double(r(2)),
double(r(3)), double(r(4)), double(r(5)));
mavlink_log_info(_mavlink_fd, "[lpe] S_I: %5.2f %5.2f %5.2f %5.2f %5.2f %5.2f",
double(S_I(0, 0)), double(S_I(1, 1)), double(S_I(2, 2)),
double(S_I(3, 3)), double(S_I(4, 4)), double(S_I(5, 5)));
mavlink_log_info(_mavlink_fd, "[lpe] r: %5.2f %5.2f %5.2f %5.2f %5.2f %5.2f",
double(r(0)), double(r(1)), double(r(2)),
double(r(3)), double(r(4)), double(r(5)));
_gpsFault = FAULT_MINOR;
}
// trust GPS less
S_I = ((C * _P * C.transpose()) + R * 10).inverse();
} else if (_gpsFault) {
_gpsFault = FAULT_NONE;
mavlink_log_info(_mavlink_fd, "[lpe] GPS OK");
warnx("[lpe] GPS OK");
}
// kalman filter correction if no hard fault
if (_gpsFault == FAULT_NONE) {
Matrix<float, n_x, n_y_gps> K = _P * C.transpose() * S_I;
_x += K * r;
_P -= K * C * _P;
}
_time_last_gps = _timeStamp;
}
void BlockLocalPositionEstimator::correctVision()
{
Matrix<float, 3, 1> y;
y.setZero();
y(0) = _sub_vision_pos.get().x - _visionHome(0);
y(1) = _sub_vision_pos.get().y - _visionHome(1);
y(2) = _sub_vision_pos.get().z - _visionHome(2);
// vision measurement matrix, measures position
Matrix<float, n_y_vision, n_x> C;
C.setZero();
C(Y_vision_x, X_x) = 1;
C(Y_vision_y, X_y) = 1;
C(Y_vision_z, X_z) = 1;
// noise matrix
Matrix<float, n_y_vision, n_y_vision> R;
R.setZero();
R(Y_vision_x, Y_vision_x) = _vision_xy_stddev.get() * _vision_xy_stddev.get();
R(Y_vision_y, Y_vision_y) = _vision_xy_stddev.get() * _vision_xy_stddev.get();
R(Y_vision_z, Y_vision_z) = _vision_z_stddev.get() * _vision_z_stddev.get();
// residual
Matrix<float, n_y_vision, n_y_vision> S_I = ((C * _P * C.transpose()) + R).inverse();
Matrix<float, n_y_vision, 1> r = y - C * _x;
// fault detection
float beta = sqrtf((r.transpose() * (S_I * r))(0, 0));
if (beta > _beta_max.get()) {
if (!_visionFault) {
mavlink_log_info(_mavlink_fd, "[lpe] vision position fault, beta %5.2f", double(beta));
warnx("[lpe] vision position fault, beta %5.2f", double(beta));
_visionFault = FAULT_MINOR;
}
// trust less
S_I = ((C * _P * C.transpose()) + R * 10).inverse();
} else if (_visionFault) {
_visionFault = FAULT_NONE;
mavlink_log_info(_mavlink_fd, "[lpe] vision position OK");
warnx("[lpe] vision position OK");
}
// kalman filter correction if no fault
if (_visionFault == FAULT_NONE) {
Matrix<float, n_x, n_y_vision> K = _P * C.transpose() * S_I;
_x += K * r;
_P -= K * C * _P;
}
_time_last_vision_p = _sub_vision_pos.get().timestamp_boot;
}
void BlockLocalPositionEstimator::correctmocap()
{
Matrix<float, n_y_mocap, 1> y;
y.setZero();
y(Y_mocap_x) = _sub_mocap.get().x - _mocapHome(0);
y(Y_mocap_y) = _sub_mocap.get().y - _mocapHome(1);
y(Y_mocap_z) = _sub_mocap.get().z - _mocapHome(2);
// mocap measurement matrix, measures position
Matrix<float, n_y_mocap, n_x> C;
C.setZero();
C(Y_mocap_x, X_x) = 1;
C(Y_mocap_y, X_y) = 1;
C(Y_mocap_z, X_z) = 1;
// noise matrix
Matrix<float, n_y_mocap, n_y_mocap> R;
R.setZero();
float mocap_p_var = _mocap_p_stddev.get()* \
_mocap_p_stddev.get();
R(Y_mocap_x, Y_mocap_x) = mocap_p_var;
R(Y_mocap_y, Y_mocap_y) = mocap_p_var;
R(Y_mocap_z, Y_mocap_z) = mocap_p_var;
// residual
Matrix<float, n_y_mocap, n_y_mocap> S_I = ((C * _P * C.transpose()) + R).inverse();
Matrix<float, n_y_mocap, 1> r = y - C * _x;
// fault detection
float beta = sqrtf((r.transpose() * (S_I * r))(0, 0));
if (beta > _beta_max.get()) {
if (!_mocapFault) {
mavlink_log_info(_mavlink_fd, "[lpe] mocap fault, beta %5.2f", double(beta));
warnx("[lpe] mocap fault, beta %5.2f", double(beta));
_mocapFault = FAULT_MINOR;
}
// trust less
S_I = ((C * _P * C.transpose()) + R * 10).inverse();
} else if (_mocapFault) {
_mocapFault = FAULT_NONE;
mavlink_log_info(_mavlink_fd, "[lpe] mocap OK");
warnx("[lpe] mocap OK");
}
// kalman filter correction if no fault
if (_mocapFault == FAULT_NONE) {
Matrix<float, n_x, n_y_mocap> K = _P * C.transpose() * S_I;
_x += K * r;
_P -= K * C * _P;
}
_time_last_mocap = _sub_mocap.get().timestamp_boot;
}